1,3,7,9-Tetramethylpyrimido[5,4-g]pteridine-2,4,6,8-(1H,3H,7H,9H)-tetraone (the tetraone) is a compound which has been described in the prior art to be a chemical which has non-specific utility. U.S. Pat. No. 2,561,324, for example, alleged it to be a new chemical compound which had utility either as a "pharmaceutical" or as an intermediate in the preparation of other organic chemicals which might have utility as therapeutic agents.
U.S. Pat. No. 2,581,889 disclosed a method for preparing pyrimidopyrazines in general. The preparation of the tetraone, which is the active ingredient of the present invention, was described in Examples 9 and 10. Again, no specific biological activity was described for this compound.
Japanese Pat. No. 51001496 alleged that the N-oxide of the tetraone had anti-cancer activity in mice.
None of the art, therefore, has described any specific pharmaceutical utility for 1,3,7,9-tetramethylpyrimido[5,4-g]pteridine-2,4,6,8-(1H,3H,7H,9H)-tetraone . Certainly, no utility which would suggest any effect on the renal system is described by the art known to the applicants.